The Polish Banks’ Association head said earlier this week some banks were working on a proposal to freeze Swiss franc-denominated mortgage installments at the franc’s December rate, in a reaction to a 20-percent Swiss franc surge against the zloty since Switzerland abandoned its currency cap.

“Any plans for changing the whole structure of the market in reaction to FX moves that could last a week, a month, a year or two, maybe, have to be done very carefully,” Szczurek told reporters at the World Economic Forum in Davos, Switzerland.

“Fixing the exchange rate at the level of December for example ... could turn out to be disastrous for clients five years down the line,” he also said.

Poland, which was the country affected most in the region by Swiss central bank’s surprise decision last week to scrap its cap on the value of the franc, is still looking for measures that could help 550,000 Swiss-franc denominated mortgage holders in an election year.

Poland’s stocks of franc-denominated home loans, worth about $36 billion before the scrapping of the franc cap, represent 8 percent of the CEE’s biggest economy gross domestic product (GDP).

Most Polish banks confirmed they would ease interest rates on such mortgages, in line with clauses written into contracts with home buyers, and also said they would not impose additional collateral, that could drown their clients.

A longer-term solution, however, may await the outcome of a European Central Bank decision on Thursday widely expected to launch a sovereign bond-buying program that could push the franc even higher.

Home buyers across the region took out loans denominated in Swiss francs in the early 2000s, attracted by interest rates in the low single digits that compared with double-digit rates on mortgages in their local currencies.

They had already faced rising repayments as the franc strengthened with the onset of the global financial crisis in 2008, but repayments have soared since last week, with the franc jumping to 4.3 from 3.6 zloty within a few minutes last Thursday. (Writing by Marcin Goclowski; Editing by Toby Chopra)